Culture

Moonflower is a tender perennial vine that is winter hardy to USDA Zones 10-12. In St.Louis, it is grown as an annual in moist, well-drained soils in full sun. This vine needs a support structure upon which to grow. It is easily grown from seed. Start seed indoors about 6-8 weeks before last spring frost date. Notch seed coat with a knife before planting to promote better germination. Seed could be started outdoors after last frost date, but the onset of bloom would occur unacceptably late in summer. Take new young plants outdoors about 1-2 weeks after last spring frost date. Once established, growth is rapid. Seeds may be harvested in fall, but only mature seeds that have fully ripened on the vine are of value. Plants grown in containers could be brought inside in fall for overwintering, albeit with some difficulty, but most gardeners simply start new seed indoors each spring.

Noteworthy Characteristics

Native to tropical America, moonflower is a tender perennial vine that is grown in St. Louis as a warm weather annual. It is noted for its fragrant nocturnal white blooms (moonflowers) and its deep green foliage. Although it will grow to 70’ or more in tropical climates, it typically reaches 10-15’ in a single season as an annual. Milky-juiced, somewhat prickly, twining stems are clad with large, rounded, broad-ovate, deep green leaves (4-8” long) with cordate bases. Fragrant, white flowers (to 6” diameter) bloom at dusk from mid-summer into fall. Flowers unfold in early evening before nightfall from attractive spiraled tubular flower buds. Flowers remain open all night and eventually close before noon the following day. Flowers attract night-flying moths. This plant is synonymous with and formerly known as Ipomoea bona-nox and Calonyction aculeatum.